Testosterone

Testosterone is the main male hormone produced by the testicles. It is responsible for inducing puberty and maintaining secondary male sexual characteristics. During puberty, testosterone levels are at their lifetime peak. Testosterone production begins to decline at about age 25 and continues to fall with age.

Testosterone blood testing is often done to aid in the diagnosis of sexual dysfunction or infertility. It is less frequently studies to aid in the diagnosis of a variety of complicated hormonally influenced diseases.

While low testosterone is not usually a cause of impotence, a depressed testosterone may be an important factor.